Crowd mount

ABSTRACT

A crowd handle mount for fixed boom shovels wherein the crowd handle is attached at its front end to a pivoted stiff leg in conventional fashion, and has its back end supported on a vertical strut that is pivotally mounted at its bottom on the shovel rotating frame and pivotally connected at its top to the crowd handle, whereby the rotating frame, stiff leg, crowd handle and strut form a four bar linkage. The crowd can be moved in crowd and retract directions by rope means reeved over sheaves on the crowd handle and in the gantry, or by means of a rack on the crowd handle and a pinion mounted in the gantry.

United States Patent Messenger, Jr.

[ Mar. 14, 1972 Primary Examiner-Gerald M. Forlenza Assistant Examiner.lerold M. Forsberg Attorney-Mason, Fenwick & Lawrence [5 7] ABSTRACT A crowd handle mount for fixed boom shovels wherein the crowd handle is attached at its front end to a pivoted stiff leg in conventional fashion, and has its back end supported on a vertical strut that is pivotally, mounted at its bottom on the shovel rotating frame and pivotally connected at its top to the crowd handle, whereby the rotating frame, stiff leg, crowd handle and strut form a four bar linkage. The crowd can be moved in crowd and retract directions by rope means reeved over sheaves on the crowd handle and in the gantry, or by means of a rack on the crowd handle and a pinion mounted in the gantry.

7 Claims, 5 Drawing Figures PATENTEUMAR 14 1972 3, 648 864 sum 1 [IF 4 INVENTOR Cam. E. Messeucerz, Ira.

YDQSMJW fume ATTORNEYS Pmimmmm 1972 3,648,864

SHEET 2 UF 4 1N VENTOR Cam. EMesseucea, 3'2.

ATTOR NEY8 PATENT EUMAR 14 m2 3, 648 864 SHEET 3 BF 4 INVENTOR CARL E.Masssn :ez,3 \2- milm iwasmdflmw ATTORNEYS PATENTEDMAR 14 m2 3,648 864 SHEET Q UF 4 I j/ ...l/- I m I CAm. E. Messeucezj' n.

ATTORNEYS CROWD MOUNT BACKGROUND OF THE INVENTION This invention relates to power shovels of the knee-action type, and more particularly to the crowd mechanisms of such shovels.

The knee-action shovel is a fixed boom shovel, with the dipper stick, or handle, being pivotally attached at its end to the top of a stiff leg pivotally mounted on the rotating frame of the machine. The crowd mechanism has included a crowd handle pivotally connected at its front end on the common pivot for the stiff leg and dipper handle, with the back end of the crowd handle being reciprocally mounted in the top of the A-frame, or gantry. The crowd handle is reciprocated by rack and pinion drive, or by means of a rope drive consisting of crowd and retract cables. With either form of drive, the crowd handle is mounted in the top of the gantry, with the handle weight being supported by a roller, or rollers, in the gantry. When the crowd handle is in fully retracted position, a considerable length of crowd handle projects unsupported to the rear of the gantry.

As the size of shovels, particularly stripping shovels, has steadily increased to the point where operating shovels are of almost unbelievable size, a problem has arisen due to the necessary weight of the crowd handle. Crowd handles are now made weighing many thousands of pounds, and the unsupported overhang of the retracted crowd handle has required heavier and heavier construction to tend to overcome the bending moment of the crowd handle about the supporting roller in the gantry. This problem has been aggravated in shovels having a rope crowd, for the crowd sheaves are usually carried at the back end of the crowd handle. Thus, the greatest weight is at the end of the unsupported crowd handle lever arm at the rear of the gantry. All attempts to stiffen the crowd handle have resulted in increasing the weight.

In the conventional crowd handling mounting, it has been necessary to provide some means in the gantry, either in a yoke supporting the crowd handle, or other structure in the gantry, to limit lateral movement of the crowd handle to preserve alignment as the handle moves. This, additionally places strains upon the gantry structure, as well as increases the weight, cost and complication of the crowd and gantry structures.

SUMMARY OF THE INVENTION The principal object of the present invention is to provide an improved mounting for crowd handles of shovels, to drastically reduce bending strains in the handle, relieve the gantry top of the weight of the handle and provide a more balanced action for the handle.

A more specific object of the invention is to provide means to continuously support the back end of the crowd handle throughout its full range of movement.

Another object is to provide a modified four-bar linkage as a crowd handle mounting.

A further object is the provision of a crowd handle mount wherein the back end of the handle is supported to reduce bending strains and permit the handle to be constructed as a simple column.

Yet another object is to provide a pivoted strut, or equalizing arm, to support the back end of a crowd handle to bear the crowd handle weight and the weight of cable sheaves if a rope crowd is used.

A still further object of the invention is to provide an improved crowd handle mount wherein both ends of the crowd handle are connected to pivoted legs to carry the crowd handle weight and to stabilize the crowd handle movement without need for other handle restraining means.

It is also an object of the invention to provide a crowd handle mount which is adaptable to either rack and pinion or rope drive systems.

Other objects of the invention will become apparent from the following description of practical embodiments thereof,

when taken in conjunction with the drawings which accompany, and form part of, this specification.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of a knee-action shovel having the improved crowd handle mount;

FIG. 2 is an enlarged view of a portion of the machine frame and house, the gantry and the crowd handle and its improved mounting means;

FIG. 3 is a vertical section through the crowd handle, taken on the line 3-3 of FIG. 2 looking toward the gantry, the view being shown on a still further enlarged scale;

FIG. 4 is a vertical section taken on the line 4-4 of FIG. 2, parts of the crowd handle equalizing arm being broken away; and

FIG. 5 is a view similar to FIG. 2, illustrating the crowd mount as applied to a rack and pinion drive arrangement.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 5 Referring first to FIG. 1 on the drawings, a typical knee-action shovel is shown. The shovel includes a base 1 supported upon crawlers 2. Rotatably supported upon the base-isa platform 3 upon which suitable framing and a house 4 arecarried. The platform also supports an A-frame, or gantry, 5, which rises considerably above the top of the house 4. A boom 6 has its foot pivotally mounted on the platform, at 7, and its upper end is supported at predetermined, fixed position by means of pendants connected to the boom tip and the top of the gantry. The usual means for lowering the boom is not shown.

A stiff leg 9 is also pivotally carried by the platform 3, and

the stifi' leg is connected to the platform by means of foot pins 10. The upper end of the stiff leg is pivotally connected at 11 to the end of .a dipper handle 12, which carries the usual dipper 13. A hoist line 14 is reeved about sheaves connected to the dipper, the boom point, and the gantry, and is wound upon a hoist drum 15 mounted on the platform 3. A crowd handle 16 has its forward end connected to the pivot 11 interconnecting the dipper handle and stifi" leg. The crowd handle is moved in and out to rock the stiff leg about its foot pins to move the dipper handle and dipper forward into the bank in well known manner.

Referring now to FIGS. 1 through 4, the new crowd handle mount is illustrated in connection with a rope crowd. The back end of the crowd handle is supported upon a strut, or equalizing arm, 17, having its lower end pivotally connected at 18 to a supporting frame 19 rising from the house and crane rail framing 20. The upper end of the equalizing arm is pivotally connected to the underside of the crowd handle 16 by a pivot 21 located adjacent the back end of the crowd handle. This arrangement provides a modified four-bar linkage consisting of a rotating frame (that is, the platform and house), the equalizing arm 17, crowd handle 16 and stiff leg 9. This linkage can be moved so that the crowd handle will be reciprocally moved backward and forward, and the linkage can be so designed that the center line of the crowd handle will pass through, or within specified limits close to, a chosen point in the gantry. When so designed, and constructed, the crowd handle, during its full range of movement, will remain in fixed relation to a specified point in the gantry, or move about a specified point, as desired. This feature becomes important in connection with the forces to be applied in moving the crowd handle through its crowd and retract cycles.

In the form of the invention shown in FIGS. I through 4, the crowd handle is moved by means of crowd cables and retract cables. In order to apply the required forces, the cables are shown doubled, and on each side of the crowd handle. As the reeving is duplicated on opposite sides of the handle, it will only be necessary to describe the cables on one side.

Crowd cable 22 is dead ended by passing around a sheave 23 fixed to the upper part of the gantry 5. The two flights of the cable extend rearwardly and around sheaves 24, mounted side by side on shaft 25 fixed to the back end of the crowd handle 16. The two flights then extend forwardly around sheaves 26 mounted upon a shaft 27 carried in the gantry. The two flights then pass downwardly about a suitable drum 28 carried within the house 4. A retract cable 29 is anchored at a dead end sheave 30 mounted in the gantry and facing in the opposite direction from the sheave 23. The two flights of the retract cable 29 pass rearwardly around sheaves 31 mounted on shaft 32 carried by the crowd handle near its front end. From sheaves 31, the two flights of cable 29 pass forwardly around sheaves 33 also mounted on shaft 27 in the gantry 5. The cables then extend downwardly to drum 28, where they are wound oppositely to the crowd cable 22. Of course, there may be separate drums for the separate cables. For purposes of illustration, however, only one need be shown. It will be apparent that rotation of the drum in a counterclockwise direction will wind up the crowd cable and simultaneously pay out retract cable so that the crowd handle will move in a crowding direction, that is to the left as viewed in FIG. 2. Reverse rotation of the drum will wind up retract cable and pay out crowd cable to move the crowd handle in the opposite direction.

It will be noted from FIG. 3 that the crowd handle moves through a vertical opening 34 in the top of the gantry, and that the sides of the opening are spaced from the sides of the crowd handle. This will allow the handle complete freedom of movement without restriction by the gantry. The handle simply moves through the gantry and has no contact with it.

Due to the fact that the crowd handle is positively supported front and back, and there is no rolling support for the crowd handle intermediate its ends, there is no unsupported overhang with its resulting bending moment. Therefore, the crowd handle can be constructed as a simple column to withstand the longitudinal strains applied during crowding. It will be noted also that the sheaves at the back of the crowd handle have their weight supported directly by the equalizing arm. Although not shown, it is apparent that the pivot between the equalizing arm and the crowd handle could be the shaft 25 upon which the sheaves 24 are mounted. Not only does this structure reduce the overall weight of the crowd mechanism, it also provides a more stable and balanced movement for the crowd handle and an overall simplified construction. The stresses upon the gantryrare limited to those imposed by the crowding forces and the gantry is relieved of the great weight of the crowd handle.

Turning now to FIG. 5 of the drawings, the improved crowd handle mount is illustrated as applied to a shovel having a rack and pinion drive for the crowd handle.

In this form of the invention, the rotating frame 35 includes a house and crane rail framing 36, as before. A gantry 37 rises through the house and projects to a considerable distance above the house. The upper portion of a stiff leg 38 is shown, and it will be understood that the bottom of the stiff leg is pivotally mounted on the rotating platform as in the previous form.

A crowd handle 39 has its forward end connected to the top of the stiff leg by a pivotal connection 40. The back end of the crowd handle is pivotally connected at 41 to the top of a crowd strut, or equalizing am, 42, that has its lower end pivotally mounted at 43 to the rotatable frame structure as before.

A rack 44 is fixed t0 the underside of the crowd handle and is in meshing engagement with a pinion 45 mounted on a shaft 46 mounted in the top of the gantry 37. The pinion will be driven by means of a suitable motor, not shown. Rotation of the pinion will cause the crowd handle to move forward in a crowding direction, or to move rearwardly to retract, as desired.

In connection with the first described form of the invention, it was stated that the geometry of the stiff leg, equalizing arm, the length of the crowd handle and the respective pivots making up the four-bar linkage was such that the center line of the crowd handle remained at, or within specified limits close to, a

fixed point in the gantry. In the case of the first described form, this point would be the center of the shaft on which the sheaves 26 and 33 were mounted, to provide for the most efficient action of the crowd and retract cables. In that form of the invention disclosed in FIG. 5, however, the design will be such that the center line of the crowd handle will always remain tangent to an arc struck from the center of the shaft 46, which arc will be of sufficient radius to hold the rack 44 in proper meshing relation with the pinion 45 without imposing the weight of a crowd handle on the pinion. In other words, the rack will be free running relative to the pinion without the binding effect of the crowd handle weight being imposed upon the meshing teeth.

While two forms of the invention have been shown, the crowd handle and its mounting means are the same in both. Only the means for moving the crowd handle are different. Both the rope actuated crowd and the rack and pinion are known means for operating a crowd handle. In both forms, the crowd mounting will have the same advantages and the crowd will be supported and will move in the same manner.

While in the above two embodiments of the invention have been shown, it will be understood that the specific details of construction shown and described are merely by way of illustration, and the invention can take other forms within the scope of the appended claims.

What is claimed is:

l. A crowd mounting for power shovels having a rotating frame, a stiff leg pivotally mounted at its bottom on the rotating frame and having its top pivotally connected to a dipper handle, and a gantry carried by and forming part of the rotat ing frame, the crowd mounting comprising, a crowd handle pivotally supported at its front end on the top of the stiff leg, a strut pivotally connected at its bottom to the rotating frame for swinging movement in the plane of movement of the stiff leg, means connecting the top of the strut to the back end of the crowd handle, whereby the crowd handle can be moved reciprocally in a path defined by the arcs of swinging movement of the points of connection of the crowd handle to the stiff leg and to the strut, and means carried in part by the crowd handle and in part by the gantry to impart reciprocatory movement to the crowd handle.

2. A crowd mounting as claimed in claim I wherein, the means to impart reciprocatory movement to the crowd handle includes sheaves carried by the crowd handle and in the top of the gantry, and crowd and retract cables reeved about the sheaves.

3. A crowd mounting as claimed in claim 1 wherein, the means to impart reciprocatory movement to the crowd handle includes a rack on the bottom of the crowd handle, a pinion carried by the gantry and means to drive the pinion.

4. A crowd mounting as claimed in claim 3 wherein, the pinion is mounted in the gantry at such point relative to the path of reciprocatory movement of the crowd handle that the pitch line of the rack remains tangent to the pitch circle of the pinion at all positions of movement of the crowd handle.

5. A crowd mounting as claimed in claim 1 wherein, the means to impart reciprocatory movement to the crowd handle includes sheaves in the gantry top, sheaves on the crowd handle, a crowd drum carried .by the rotating drum, and crowd and retract cables reeved about the sheaves and wound in opposite phase on the crowd drum.

6. A crowd mounting as claimed in claim 1 wherein, the means for imparting reciprocatory movement to the crowd handle includes a sheave on the gantry, a sheave on the rear end of the crowd handle, a crowd drum on the rotating frame, and a crowd cable anchored at one end to the gantry and reeved about the sheave at the rear end of the crowd handle, over the sheave in the gantry, and wound in one direction upon the crowd drum, a second sheave in the gantry, a sheave at the front end of the crowd handle, and a retract cable anchored at one end in the gantry and reeved over the sheave at the front end of the crowd handle, about the second sheave in the gantry, and wound in the opposite direction from the crowd cable upon the crowd drum.

7. A crowd mounting as claimed in claim 1 wherein, the gantry has a passageway in its top in the plane of movement of the crowd handle, and the crowd handle moves unrestricted through the passageway.

n t 1: a: 5 

1. A crowd mounting for power shovels having a rotating frame, a stiff leg pivotally mounted at its bottom on the rotating frame and having its top pivotally connected to a dipper handle, and a gantry carried by and forming part of the rotating frame, the crowd mounting comprising, a crowd handle pivotally supported at its front end on the top of the stiff leg, a strut pivotally connected at its bottom to the rotating frame for swinging movement in the plane of movement of the stiff leg, means connecting the top of the strut to the back end of the crowd handle, whereby the crowd handle can be moved reciprocally in a path defined by the arcs of swinging movement of the points of connection of the crowd handle to the stiff leg and to the strut, and means carried in part by the crowd handle and in part by the gantry to impart reciprocatory movement to the crowd handle.
 2. A crowd mounting as claimed in claim 1 wherein, the means to impart reciprocatory movement to the crowd handle includes sheaves carried by the crowd handle and in the top of the gantry, and crowd and retract cables reeved about the sheaves.
 3. A crowd mounting as claimed in claim 1 wherein, the means to impart reciprocatory movement to the crowd handle includes a rack on the bottom of the crowd handle, a pinion carried by the gantry and means to drive the pinion.
 4. A crowd mounting as claimed in claim 3 wherein, the pinion is mounted in the gantry at such point relative to the path of reciprocatory movement of the crowd handle that the Pitch line of the rack remains tangent to the pitch circle of the pinion at all positions of movement of the crowd handle.
 5. A crowd mounting as claimed in claim 1 wherein, the means to impart reciprocatory movement to the crowd handle includes sheaves in the gantry top, sheaves on the crowd handle, a crowd drum carried by the rotating drum, and crowd and retract cables reeved about the sheaves and wound in opposite phase on the crowd drum.
 6. A crowd mounting as claimed in claim 1 wherein, the means for imparting reciprocatory movement to the crowd handle includes a sheave on the gantry, a sheave on the rear end of the crowd handle, a crowd drum on the rotating frame, and a crowd cable anchored at one end to the gantry and reeved about the sheave at the rear end of the crowd handle, over the sheave in the gantry, and wound in one direction upon the crowd drum, a second sheave in the gantry, a sheave at the front end of the crowd handle, and a retract cable anchored at one end in the gantry and reeved over the sheave at the front end of the crowd handle, about the second sheave in the gantry, and wound in the opposite direction from the crowd cable upon the crowd drum.
 7. A crowd mounting as claimed in claim 1 wherein, the gantry has a passageway in its top in the plane of movement of the crowd handle, and the crowd handle moves unrestricted through the passageway. 